Balloon catheters for non-continuous lesions

Abstract

Balloon catheters according to the present invention have surface contours with protrusions and grooves to make non-continuous lesions. There is a heating element inside the balloon. The balloon will be filled with a fluid before ablation to expand the balloon for tissue contact, and to transfer heating energy from the heating element to the tissue in contact with the balloon. Since the balloon surface has contours with grooves and protrusions, the tissue contact will not be continuous along the balloon surfaces, and therefore the ablation on the tissue will not be continuous. The energy transmitter can be ultrasound transducer, electrical resistant heater, and microwave antenna.

I claim:  
     
       1. A medical device used to circumferentially ablate the interior surface of hollow human body lumen comprising: 
       a balloon catheter having an elongated tubular shaft having a catheter axis and a distal end; said tubular shaft providing a fluid passageway;  
       an inflatable balloon attached to said tubular shaft adjacent said distal end; said balloon having an outer surface and an inner surface that defines a main chamber that is in communication with said fluid passageway of said tubular shaft;  
       said outer surface of said balloon having a configuration defined by multiple outwardly extending protrusions around said outer surface; said protrusions being hollow to form sub-chambers that are in communication with said main chamber of said balloon; the outer surface distance between said protrusions define grooves whereby when said balloon is inflated by a pressurized fluid in a hollow human body lumen a sufficient amount to press said outer surfaces of said protrusions against the interior tissue surface of said lumen, said grooves will provide passageways that prevent complete blockage of said hollow body lumen; when the fluid is heated to a temperature high enough for tissue ablation, discontinuous lesions will be produced on the interior surface of the tissue in said lumen where said protrusions contact said tissue.  
     
     
       2. A medical device as recited in  claim 1  wherein said protrusions have an elongated configuration and said grooves between said protrusions are also elongated. 
     
     
       3. A medical device as recited in  claim 2  wherein said elongated protrusions and grooves are parallel to said catheter axis. 
     
     
       4. A medical device as recited in  claim 2  wherein said elongated protrusion and grooves are non-parallel to said catheter axis. 
     
     
       5. A medical device as recited in  claim 1  wherein said protrusions are non-elongated. 
     
     
       6. A medical device as recited in  claim 1  wherein said protrusions and grooves are symmetrically oriented on said outer surface of said balloon. 
     
     
       7. A medical device as recited in  claim 1  wherein said protrusions are randomly oriented on said outer surface of said balloon. 
     
     
       8. A medical device as recited in  claim 1  further comprising heating means for heating a pressurized fluid when it is pumped into said balloon. 
     
     
       9. A medical device as recited in  claim 8  wherein said heating means is an electrical resistant heater. 
     
     
       10. A medical device as recited in  claim 8  wherein said heating means is a microwave antenna. 
     
     
       11. A medical device as recited in  claim 8  wherein said heating means is an ultrasound transducer from which both ultrasound wave and heat are transferred through the fluid to body tissue in contact with said outer surface of said protrusions for ablation. 
     
     
       12. A medical device as recited in  claim 1  further comprising at least one thermocouple attached to said balloon surface for temperature measurement. 
     
     
       13. A method of ablating body lumen tissue of nose, esophageal, ostium cardiacum, stomach, pylori, intestine, anus, urethra and bladder outlet, the method comprising the following steps: 
       (A). providing a balloon catheter having an elongated tubular shaft having a catheter axis and a distal end, said tubular shaft providing a fluid passageway; an inflatable balloon attached to said tubular shaft adjacent said distal end, said balloon having an outer surface and an inner surface that defines a main chamber that is in communication with said fluid passageway of said tubular shaft; said outer surface of said balloon having a configuration defined by multiple outwardly extending protrusions around said outer surface, said protrusions being hollow to form sub-chambers that are in communication with said main chamber of said balloon; the outer surface distance between said protrusions define grooves;  
       (B). inserting said balloon catheter into a body lumen to be treated;  
       (C). inflating said balloon with a sufficient amount of fluid to press said outer surfaces of said protrusions against the interior tissue surface of said lumen; said grooves providing passageways that prevent complete blockage of said hollow body lumen; and  
       (D). heating said fluid to a temperature high enough for tissue ablation producing multiple discontinuous lesions on the interior surface of said tissue in said lumen where said protrusions contact said tissue.  
     
     
       14. The method as recited in  claim 13  wherein said protrusions of said balloon catheter have an elongated configuration and said grooves between said protrusions are also elongated. 
     
     
       15. The method as recited in  claim 14  wherein said elongated protrusions and grooves are parallel to said catheter axis. 
     
     
       16. The method as recited in  claim 14  wherein said elongated protrusions and grooves are non-parallel to said catheter axis. 
     
     
       17. The method as recited in  claim 14  wherein said protrusions are non-elongated. 
     
     
       18. The method as recited in  claim 14  wherein said protrusions and grooves are symmetrically oriented on said outer surface of said balloon. 
     
     
       19. The method as recited in  claim 14  wherein said protrusions are randomly oriented on said outer surface of said balloon. 
     
     
       20. The method as recited in  claim 14  wherein the fluid is heated by an electrical resistant heater in said balloon. 
     
     
       21. The method as recited in  claim 14  wherein the fluid is heated by an electric microwave antenna in said balloon. 
     
     
       22. The method as recited in  claim 14  wherein the fluid is heated by an ultrasound transducer from which both ultrasound wave and heat are transfered through said fluid to body tissue in contact with said outer surface of said protrusions for ablation. 
     
     
       23. The method as recited in  claim 14  wherein said balloon catheter further comprises at least one thermocouple attached to said balloon surface for temperature measurement.